Alfa Romeo takes the covers off production 4C Spider in Detroit

Alfa Romeo has used the North American International Motor Show (NAIAS) to launch the convertible version of its 4C sportscar. The 4C Spider retains the coupe's lightweight carbon fiber construction while allowing drivers to get closer to nature or, if you'd prefer, to the car's heavily turbocharged four-cylinder engine.

Powering the Spider is the same 1.75-liter, 4-cylinder motor that hides under the coupe's hood. Producing 237 hp (177 kW), the 4C's engine is turbocharged for prodigious low down torque: the engine's full 350 Nm (258 lb.ft) of torque is available between 2,200 and 4,250 rpm. The dual-clutch gearbox from the 4C Coupe also carries over.

According to Alfa Romeo's Head of North America, Reid Bigland, the 4C Spider's removable top allows drivers to experience the car from "an entirely new perspective" – be it through the standard removable soft top, or the optional carbon fiber lid.

Differentiating the 4C Spider from its Coupe brethren (besides the missing roof, of course) is a carbon fiber windshield surround and a set of new alloy wheels, as well as an Akrapovic exhaust system that swaps the standard car's quad tailpipes for a set of center-mounted units that should give the engine a more distinctive sound.

Very few tweaks have been made from the 4C Spider Concept released last year: cleaner headlamp units (which replace the carbon surrounded, bug-eyed units on the launch Coupe) have carried over from the car shown at Geneva, as have the aluminum wheels featured on the Geneva design preview.

The Spider's interior is brightened up by standard contrast stitching, which is available in a number of different color combinations depending on whether owners decide to tick the "track pack" on the options list.

If you like the look of the 4C without its top, you don't have to wait long. Alfa Romeo says the car should arrive in North American dealerships this summer, although there is no mention of pricing.